If you like antique engines, vintage tractors or old iron, please register and join us. When you register and log in, lots more features open up to your computer screen. Give us a try and register. See our Welcome Page!

I started my Onan DJE today. I run it for a few minutes every several weeks. I have accumulated a few questions that I would like clarified a little bit.

1. It feels as though the starter is a little "weak". Like I would engage the start switch, the starter would make a WHAM sound but the engine would barely move. Another time, then another, and then it would finally spin fast enough to start. After that it starts easily.

My starting cables are very decent (1 gauge, if I recall it correctly), though I could check how well they are attached. I keep the battery on a nice automatic charger that keeps it 100% charged and wakes up once in a while to recharge it.

What would explain it?

2. After startup, it smokes a lot (like really a lot) for a minute or two. I only realized how different it is after I dealt with a like new Cummins L423D, which does NOT smoke as much.

I can make a video of that.

During same time during startup, it "misses" a beat once every several cycles. Again a video (with sound) could clarify.

Is it possible that you have a leaking injector? Is it mechanically possible for an injector to leak? If the unit sits a few weeks between runs, maybe fuel is seeping through a leaking injector and collecting in the cylinder.

When you first crank it over, the starter wouldn't like trying to compress a fluid... after a few revolutions, with the valves opening to let fluid out, it would spin faster and finally start, giving you the heavy smoke and then smooth starting.

Does the DJE fuel system maintain pressure between the fuel pump and injectors at any point? If it's a mechanical linkage between engine and fuel pump (i.e. not an electrical fuel pump that's off when the engine is off) then perhaps pressure is being maintained somewhere and feeding a leaky injector.

If this were true, a test would be to pull the exhaust manifold after it sat a while - assuming it's not a big ordeal - and see if fuel spits out when you try to crank it.

Is this the same one that had the failing injector pump? Could crud from the deteriorating parts have gotten into an injector and is partially jamming it open?

I have 2 of these 7kW's in my shed and have worked with like models for years(MEP 002&003). All the 2 and 4 cylinder air cooled onan diesels I saw sputtered, smoked profusely, skipped, and popped and generally ran rough for the first minute when starting cold. Not the answer you are looking for, but it is normal from what I have seen.....

I thought mine were "DJB" and the 4 cyl was a "DJE" but might not have my facts straight.

I think this may be your problem. The 1 minute glow cycle of the DJx series, plus the starting takes a toll on the battery. A few minutes running will not allow the battery to recover. Load it up and let it run for an hour or so - two beers worth.

There was a great thread on the Kohler side of this site about the merrits of exercising generators. I am on my way to work, and can't link it, but it isn't too hard to find.

Onan DJ engines do not like anything below sixty degrees. They will smoke and bang and miss until they get warmed up.If it clears up and runs ok you have nothing but a normal engine. With glow plug heaters going I have still seen them smoke. Just a normal DJ.

'J' series Onans usually smoke a lot on cold start up and run rough. Even worse if the injection pump timing is late. If you suspect it is oil smoke you are seeing check and make sure that someone has not installed one of the pushrod tubes upside down. This will cause a pooling of oil on top of the head and leakage past the valve guides.

My DJC (really) burps and farts and (really really) smokes on startup and generally makes people shake their heads without confidence, waiting for either the big bang or slow starvation death. They usually smirk and say something like their Gererac 4 kw is rock steady on startup, or their Honda is ALOT quieter. Just about then, I grin a little bit, and carry over my 9,600 watt 240 volt construction heater, plug it in and flip on the breaker.

It smooths right out in another couple of minutes as it warms up, the smoke tapers off to a clear pipe, and then it is rock steady. Then, it is my turn to point out that this old Onan will run this 10 kW load steady for a week, with enough reserve capacity left over to equal the entire output of their GenerJunk. All for a petty 3 litres per hour of 70 cent/litre diesel. I do like my Onan.

We also have an Onan HDKAG in the fleet, but it doesn't have anywhere near the personality of the DJ.

My DJE turns over slower than my DJC's but not to the point of stalling. They start fairly quick, but one of my C's sputtered and smoked alot more than my other one. I recently put a full 12 kw load in it and it turned the neighborhood blue for about 10 minutes then gradually after an hour was clear. (burned the paint off the muffler) It now starts faster and clears up quicker (20-30 seconds) like the other C. I doubt it had ever seen 3 KW as it was used at a race track to run a tire ballancer. I believe they all use the same starter. I got my drive, brushes and solenoid from Marc's One in Phoenix. If fitting a new drive you should carefully file each tooth Unless already perfect which I have not seen yet, to remove burs and reshape the contour of the edge where the drive hits on engagement. The teeth are soft. Don't overlook the possibility of a bad battery. I've seen many starters rebuilt because of poor starting with a fairly new battery. Check it with a tester or put another battery in that you know spins well. It requires 750CCA or better when cold. You can't get too much battery on a diesel.

Gentlemen, I want to say a big thank you to all of you. I will try to make a video. Maybe it is indeed just fine as you guys seem to say.

What is apparent to me is that I should make a good test/exercising load for this generator.

My previous test setup was VERY unsafe and was made of a bare water heater half immersed in water. Enough to test it once under constant supervision, with my hand ready to pull the plug, not safe enough to exercise it weekly.

I just purchased a 5,400 watt heating element on eBay and will make up a load by enclosing it in some sort of a air tunnel and adding a Comair Rotron Caravel fan. 5,400 watt is just about perfect for my genset (will probably be a little lower due to lower output voltage).